boost/type_traits/is_lvalue_reference.hpp
// (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes,
// Howard Hinnant and John Maddock 2000.
// (C) Copyright Mat Marcus, Jesse Jones and Adobe Systems Inc 2001
// Use, modification and distribution are subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt).
//
// See http://www.boost.org/libs/type_traits for most recent version including documentation.
// Fixed is_pointer, is_lvalue_reference, is_const, is_volatile, is_same,
// is_member_pointer based on the Simulated Partial Specialization work
// of Mat Marcus and Jesse Jones. See http://opensource.adobe.com or
// http://groups.yahoo.com/group/boost/message/5441
// Some workarounds in here use ideas suggested from "Generic<Programming>:
// Mappings between Types and Values"
// by Andrei Alexandrescu (see http://www.cuj.com/experts/1810/alexandr.html).
#ifndef BOOST_TT_IS_LVALUE_REFERENCE_HPP_INCLUDED
#define BOOST_TT_IS_LVALUE_REFERENCE_HPP_INCLUDED
#include <boost/type_traits/config.hpp>
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
# include <boost/type_traits/detail/yes_no_type.hpp>
# include <boost/type_traits/detail/wrap.hpp>
#endif
// should be the last #include
#include <boost/type_traits/detail/bool_trait_def.hpp>
namespace boost {
#if defined( __CODEGEARC__ )
BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_lvalue_reference,T,__is_reference(T))
#elif !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_lvalue_reference,T,false)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T&,true)
#if defined(BOOST_ILLEGAL_CV_REFERENCES)
// these are illegal specialisations; cv-qualifies applied to
// references have no effect according to [8.3.2p1],
// C++ Builder requires them though as it treats cv-qualified
// references as distinct types...
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T& const,true)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T& volatile,true)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T& const volatile,true)
#endif
#if defined(__GNUC__) && (__GNUC__ < 3)
// these allow us to work around illegally cv-qualified reference
// types.
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T const ,::boost::is_lvalue_reference<T>::value)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T volatile ,::boost::is_lvalue_reference<T>::value)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_lvalue_reference,T const volatile ,::boost::is_lvalue_reference<T>::value)
// However, the above specializations confuse gcc 2.96 unless we also
// supply these specializations for array types
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_lvalue_reference,T[N],false)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_lvalue_reference,const T[N],false)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_lvalue_reference,volatile T[N],false)
BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_lvalue_reference,const volatile T[N],false)
#endif
#else
#ifdef BOOST_MSVC
# pragma warning(push)
# pragma warning(disable: 4181 4097)
#endif
namespace detail {
using ::boost::type_traits::yes_type;
using ::boost::type_traits::no_type;
using ::boost::type_traits::wrap;
template <class T> T&(* is_lvalue_reference_helper1(wrap<T>) )(wrap<T>);
char is_lvalue_reference_helper1(...);
template <class T> no_type is_lvalue_reference_helper2(T&(*)(wrap<T>));
yes_type is_lvalue_reference_helper2(...);
template <typename T>
struct is_lvalue_reference_impl
{
BOOST_STATIC_CONSTANT(
bool, value = sizeof(
::boost::detail::is_lvalue_reference_helper2(
::boost::detail::is_lvalue_reference_helper1(::boost::type_traits::wrap<T>()))) == 1
);
};
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_lvalue_reference,void,false)
#ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_lvalue_reference,void const,false)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_lvalue_reference,void volatile,false)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_lvalue_reference,void const volatile,false)
#endif
} // namespace detail
BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_lvalue_reference,T,::boost::detail::is_lvalue_reference_impl<T>::value)
#ifdef BOOST_MSVC
# pragma warning(pop)
#endif
#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
} // namespace boost
#include <boost/type_traits/detail/bool_trait_undef.hpp>
#endif // BOOST_TT_IS_REFERENCE_HPP_INCLUDED